This invention relates to a mounting apparatus for a cathode-ray tube and more particularly to a mounting apparatus for providing self-alignment and cabinet size reduction.
A cathode-ray tube, such as a color picture tube, has a glass envelope that comprises a neck, a funnel and a face-plate panel. The face-plate panel includes a viewing face-plate that is surrounded by a peripheral side wall. When a cathode-ray tube is evacuated to a very low internal pressure, it is subjected to the possibility of implosion caused by the stresses produced on the tube envelope by atmospheric pressure. In order to reduce the possibility of implosion, as well as to reduce the effects of an implosion should it occur, a tension band usually is applied externally to the face-plate panel side wall. Such a tension band applies compressive forces to the side wall which redistribute the stresses in the face-plate panel.
As known in the art and shown in FIG. 1, mounting lugs 16, integral with, attached to, or disposed between the band 14 and the tube side wall, are used to support the tube 22 within a cabinet 10. Typically, the mounting lugs 16 are positioned at the corners of the tube 22 because they are dependent on the tension of the band in the corners of the tube to provide the force to hold them in place. However, set designers have found this mounting technique to be somewhat undesirable, because the internal size of a cabinet 10 must accommodate the tube 22 plus the mounting lugs 16, which adds from about 5-9 cm. to the overall dimensions of the tube 22. Due to thermal expansion characteristics of the tube and known tension bands 14, mounting lugs 16 and holes formed therein are formed larger than necessary to accommodate size and portion variations due to the thermal expansion during tube processing. Dimensioning these components to be larger contributes to increasing overall dimensions of the mounting system and set.
In assembly, a tube 22 having the tension band 14 and lugs 16 applied, is placed over an opening in a bezel 10 face down and the mounting lugs openings are aligned with bolts or studs 20 in the bezel 10. Such an alignment technique requires manual intervention to align the lugs 16 with the openings in the bezel 10. Set designers have expressed a desire for a mounting technique that would decrease the dimension of the mounting system, so that a trimmer visual appearance could be achieved. Set designers have also expressed a desire for a simpler more automated mounting technique that would allow the tube to be easily aligned within the set opening or bezel. The present invention provides mounting means, which permits a reduction in the size of the cabinet as well as a simple self-alignment apparatus for mounting the cathode-ray tube into the cabinet.
The present invention provides an improvement in the mounting of a cathode-ray tube within a bezel. The cathode-ray tube includes a unitary shellbond frame having integral mounting lugs which are positioned at locations either in the corners or off of the corners. The mounting lugs are formed with tapered sections along a depth dimension to allow a tube having the shellbond frame applied to be simply lowered into a bezel having lug receiving recesses of a complimentary shape. The tapered lug and complimentary lug receiving recess provides self-alignment of the tube before it is secured to the bezel.